Small incision lenticule extraction (SMILE) is an outpatient procedure that changes the shape of the cornea to correct refractive errors. It is FDA-approved only for the treatment of Myopia at this time.
In SMILE, topical anesthesia is applied to the surface of the eye. Next, a femtosecond laser cuts a small lens-shaped disc or lenticule of tissue within the cornea. The shape of this lenticule is calibrated to match the refractive error of the eye precisely. The surgeon then extracts the lenticule through a separate cut-down incision, also made by the laser, to produce a shape change in the cornea.
Not every patient is a candidate for SMILE. Patients with thin corneas, progressive ectasia, scars, irregular astigmatism, and a few other pathologies are ineligible. Your surgeon, or one of the optometrists in his or her practice, can determine if you are a suitable candidate during a free screening examination.
SMILE typically takes about 20 minutes to perform per eye and both eyes are usually treated during the same session. SMILE is associated with minimal to mild discomfort while it is being performed. When the topical anesthesia wears off, however, the level of discomfort increases. Most patients develop redness and tearing. There is often stinging and a gritty sensation that lasts 6 to 12 hours. Visual recovery is slower than laser-assisted in situ keratomileusis (LASIK), typically taking 2 to 7 days.
As with any procedure, there is a risk of complications with SMILE, including the possibility of an under correction or over correction. The risks should be discussed with your doctor before you undergo the procedure.
Enhancements are usually performed by photorefractive keratectomy (PRK).